There have been some reports of robberies and assaults along remote highways near China's border with Nepal and in areas of Mt. Everest.

Travelers should have small bills (RMB 10, 20 and 50 notes) for travel by taxi. Reports of taxi drivers using counterfeit RMB 50 and 100 notes to make change for large bills are increasingly common.

Health risks: Health Information for Travelers to East Asia and the Indian Subcontinent at the Centers for Disease Control and Prevention (CDC).
According to the State Departments Consular Information Sheet: All Americans traveling to China are strongly encouraged to buy foreign medical care and medical evacuation insurance prior to arrival. Travelers who want a list of modern medical facilities in China can e-mail the United States Embassy's American Citizen Services unit at AmCitBeijing@state.gov and request a list by return e-mail.

Medical Facility List.
See also Magellan's and MD Travel Health
Traveler's diarrhea and Acute Mountain Sickness (AMS)